Radioisotope and stable isotope ratios (Δ14C, δ15N) suggest larval lamprey growth is dependent on both fresh and aged organic matter in streams     

Thomas M. Evans  Amber R. Bellamy  James E. Bauer 《Ecology of Freshwater Fish》2019,28(3):365-375

Lampreys have a complex life cycle which includes a multi‐year infaunal larval stage (ammocoete). Gut content analysis has generally identified detritus (i.e., unidentifiable organic matter) as the major dietary component to ammocoetes, though algae can also be important. However, gut content preserves only a snapshot of the animal's diet and does not reflect assimilated material. In order to better characterise the nutritional sources supporting ammocoete growth, we analysed ammocoete body tissue and potential dietary sources at two streams using natural Δ¹⁴C and δ¹⁵N to estimate time‐integrated nutritional support. Bayesian isotope mixing models revealed differences in the importance of sources supporting ammocoetes between sites. Ammocoetes from a stream in a mixed land usage area (~50% agriculture, ~40% forest and ~10% developed) were primarily supported (mean: ~50%) by fresh terrestrial organic matter but were also supported by substantial contributions (mean: ~30%) by aged organic matter (AOM) and autochthonous material (algae; mean ~20%). In a predominantly forested (~90%) headwater stream, different modelling scenarios (uninformed or informed priors) suggested that algal support of ammocoete nutrition ranged from 7% to 45%. However, the model relying on informed priors developed from gut content analysis produced the low estimates, suggesting these were more reliable. When algae were a minor component of the nutrition at the forested site, ammocoetes were highly dependent on AOM (83 ± 26%; mean ± SD). Based on these findings, ammocoete growth and development are predicted to be strongly influenced by both land use and the availability of allochthonous and autochthonous materials of varying ages within streams.  相似文献   

The effect of porcine somatotropin supplementation in pigs on the lipid profile of subcutaneous and intermuscular adipose tissue and longissimus muscle.     

S L Clark  R C Wander  C Y Hu 《Journal of animal science》1992,70(11):3435-3442

The effect of porcine somatotropin (pST) on the lipid profiles of adipose tissue and muscle was investigated. Sixteen crossbred barrows were injected daily with either 3 mg of pST or a placebo. After slaughter, total lipid and fatty acid composition of raw subcutaneous (SC) adipose and intermuscular (IM) adipose tissue and longissimus muscle were determined. The SC adipose tissue from pST-treated pigs had a 7.5% decrease in total lipid content; specific fatty acids 16:0, 18:0, and 18:1(n-9)c decreased most. The IM fat from pST-treated pigs had lower levels of 16:0 and 20:0. There was no effect of pST treatment on the lipid profile of the longissimus muscle. The data suggest that pST treatment produces small but significant changes in the saturated fatty acid content of adipose tissue in pigs.  相似文献   

The immunohistochemical detection of Mycoplasma bovis and bovine viral diarrhea virus in tissues of feedlot cattle with chronic, unresponsive respiratory disease and/or arthritis.          下载免费PDF全文

D M Haines  K M Martin  E G Clark  G K Jim    E D Janzen 《The Canadian veterinary journal. La revue veterinaire canadienne》2001,42(11):857-860

The purpose of this study was to determine the frequency of selected pathogens in the tissues of a group of feedlot cattle with chronic disease (most often respiratory disease and/or arthritis). Samples of lung and joint tissues from 49 feedlot animals that had failed to respond to antibiotic therapy were tested by immunohistochemical staining for the antigens of Mycoplasma bovis, Haemophilus somnus, Pasteurella (Mannheimia) hemolytica, and bovine viral diarrhea virus (BVDV). Mycoplasma bovis was demonstrated in over 80% of cases, including in 45% of joints and 71% of lungs tested. Mycoplasma bovis was the only bacterial pathogen identified in the joints. Haemophilus somnus and Pasteurella (Mannheimia) haemolytica were found in 14% and 23% of cases, respectively, and were confined to the lungs in all instances. Infection with BVDV was demonstrated in over 40% of cases. Mycoplasma bovis and BVDV were the most common pathogens persisting in the tissues of these animals that had failed to respond to antibiotic therapy.  相似文献   

ENDOTOXAEMIA: RECENT ADVANCES IN PATHOPHYSIOLOGY AND TREATMENT     

James N.  Moore 《Veterinary anaesthesia and analgesia》1994,21(2):77-81

  相似文献   

MAGNETIC RESONANCE, ULTRASOUND AND HISTOPATHOLOGIC CORRELATION OF ACUTE AND HEALING EQUINE TENDON INJURIES     

Jeffrey R.  Crass  MD  Ronald L.  Genovese  VMD  James A.  Render  DVM  Errol M.  Bellon  MD 《Veterinary radiology & ultrasound》1992,33(4):206-216

Ultrasonography and MRI have become valuable tools for imaging of tendon injuries. The current study examines the histopathologic basis for the imaging abnormalities. Five injured equine forelimbs and two normal contralateral limbs were studied with high resolution real time ultrasound and MRI. Histologic sections were made and correlated with the diagnostic images. All lesions were readily seen by both modalities. Lesions characterized by hemorrhage, edma, and cellular infiltration were sonolucent on ultrasound and bright on MRI images. MRI returned to normal as fibrogenesis ensued. Ultrasound images remained abnormal until fibrillar reallgnment occured with completion of the healing process. High resolution real time ultrasound and MRI both accurately reflect the tissue abnormalities in acute tendon injuries. The injured horse does appear to be an effective model for correlative imaging studies of tendon injuries.  相似文献   

Beef feedlot industry.     

James Mintert 《Veterinary Clinics of North America: Food Animal Practice》2003,19(2):387-395

The United States cattle feeding sector has changed dramatically over time. Movement from an industry largely populated by farmer feeders using livestock to market their grain production to an industry composed of large, specialized, commercial cattle feeding firms has occurred since the end of World War II. Moreover, the industry also shifted geographically, moving away from the Corn Belt to the Plains as farmer feeders exited the industry. Today, the 10 largest firms in the industry likely market 22% to as much as 29% of all fed cattle produced in the United States. The shift in industry structure was at least partially motivated by the advent of improved technology. Successful implementation of rapidly evolving technology often required more intense, specialized management (and in some cases, larger operations) than was available in many farmer feeder operations. The ongoing shift away from live-weight pricing of fed cattle toward grid-based pricing could increase the need for specialized management yet again, encouraging even more industry consolidation in the future.  相似文献   

Branchial cyst in a dog     

D M Clark  M Kostolich  D Mosier 《Journal of the American Veterinary Medical Association》1989,194(1):67-68

A 7-year-old spayed German Shorthaired Pointer was determined to have a branchial cyst in the subcutaneous tissues of the cervical/facial area. Treatment had been attempted by aspiration and placement of drains, but without success; the final diagnosis was made after microscopic examination of the wall of the excised cyst. The means by which fluctuant swellings in this region may be differentiated are anatomic location and examination of full-thickness biopsy specimens of cyst walls.  相似文献   

Effects of dopamine administration on cecal mechanical activity and cecal blood flow in conscious healthy horses     

E S Clark  J N Moore 《American journal of veterinary research》1989,50(7):1084-1088

Lateral cecal arterial blood flow, carotid arterial pressure, heart rate, and mechanical activity of the circular and longitudinal muscle layers of the cecal body were measured in 7 conscious healthy horses during IV infusion of physiologic saline solution for 60 minutes (control), during a 60-minute IV infusion of dopamine (at dosages of 1, 2.5, and 5 micrograms/kg/min), and for 60 minutes after IV infusion of dopamine. The mean values for lateral cecal arterial blood flow during IV infusion of dopamine at a dosage of either 1 or 2.5 micrograms/kg/min were not significantly different from the mean values for lateral cecal arterial blood flow during IV infusion of saline solution. The mean values for lateral cecal arterial blood flow, however, were significantly greater during IV infusion of dopamine at a dosage of 5 micrograms/kg/min than the mean values for lateral cecal arterial blood flow during IV infusion of saline solution. Intravenous infusion of dopamine at 1 and 2.5 micrograms/kg/min did not significantly change the mean values for carotid arterial pressure. In contrast, the mean values for carotid arterial pressure were significantly less during IV infusion of dopamine at dosages of 2.5 and 5 micrograms/kg/min than during infusion of saline solution. The mean values for heart rate were not significantly altered by infusion of dopamine at a dosage of either 1 or 2.5 micrograms/kg/min, but infusion of dopamine at a dosage of 5 micrograms/kg/min significantly increased heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

ULTRASOUND CORNER BLADDER WALL MASS EFFECT CAUSED BY THE INTRAMURAL PORTION OF THE CANINE URETER     

James P.  Douglass  DVM  MS 《Veterinary radiology & ultrasound》1993,34(2):107-107

  相似文献   

Artificial Spawning of Tilapia Eggs1     

James M. Myers  William K. Hershberger 《Journal of the World Aquaculture Society》1991,22(2):77-82

A stripspawning methodology was evaluated for tilapia (oreochromid) species. This technique achieved an average hatching success of 68.6 ± 3.6% (N= 31). Female fecundity and spawning frequency were dependant on both genetical and husbandry factors. Egg yields for Oreochromis niloticus, O. mossambicus, and O. niloticus±O. mossambicus hybrids averaged 4.54, 10.86 and 10.36 eggs/g female/spawn, respectively. Female broodstock that were adapted to an intensive spawning regime exhibited a significant increase in fecundity. Additionally, egg survival was not affected by hydration for up to 15 minutes prior to fertilization. Results suggest that the strip spawning of tilapia species may be an efficient method of providing viable gametes for hatchery purposes.  相似文献